【摘要】 水是人类生存的命脉． 近年来随着世界人口的增加和经济的发展，人均占有水资源量越来越少，面临水资源恐慌，世界各国在大力采取节约用水的同时，都着力于开辟新水源，以缓解淡水危机．更多还原

【Abstract】 w ater is the lifeblood of hum an being. As the population increases and econom y develops, the fresh w ater resource is becom ing less and less. In order to solve the no fresh w atercrisis. Allofthe countriesare devoting m ajoreffortsto w atersaving projectand atthe sam e tim e try the bestto find outnew w ater sources.更多还原